88 Proceedings of the Biological Society of Washington. 



states that some of these bhster galls occur in the herbaria of mycologists, 

 under the name of Rhrjtisma solidaginis and R. asteris." 



From the foregoing it appears that most but not all of the Diptera 

 associated with fungi confine their feeding activities to members of the 

 fungus families Agaricaceae and Boletaceae, the sporophores of which are 

 fleshy and also to such members of the Polyporaceae which are fleshy. 

 Several exceptions are those such as a Winnertzia sp., which was bred from 

 a tough and leathery specimen of Lenzites saepiaria and Monardia lignivora 

 Felt, 1 the larvae of whch were bred from the fungus-affected heartwood of 

 Pinus rigida, where they were apparently attacking spongy as well as hard 

 wood. It further appears that as far as known, most of the more or less 

 strictly fungus inhabiting Diptera are confined to the families Mycetophili- 

 dae and Platypezidae, the members of the former being by far the most 

 numerous. By reason of their food habits, members of these families are 

 generally found in damp surroundings and are usually classed as scavengers 

 although many are not true scavengers as they do not feed upon decaying 

 vegetable matter. Most of them must of necessity have brief larval 

 periods, because many of the agarics do not last more than ten days or 

 two weeks. For many of the species definite information is lacking and 

 little is known concerning their true relations with and dependence upon 

 the lower forms of plant life. 



lUniv. State of N. Y. Bvd. 547. p. 191. ' 



